Electrical switch apparatus



Feb. 23, 1932.

D. R. FURNAS ELECTRICAL SWITCH APPARATUS Filed June ll. 1927 2 Sheets-Sheet l TMQTL o cwi/[65 es M kfw Feb. 23, 1932. D, R, FURNAS 1,846,051

ELECTRIQAL swI'rcH APPARATUS Filed June 1l. 1927 2 Sheets-Sheet 2 I ,ff

Patented F eb. 23, 1932 UNITED STATES PATENT OFFICE DON ROSS FURNAS, 0F AURORA, ILLINOIS, ASSIGNOR T0 AURORA STEEL PRODUCTS` COMPANY, OF AURORA, ILLINOIS, A CORPORATION OF ILLINOIS ELECTRICAL SWITCH APPARATUS Application ied J'une 11,

The present invention relates to circuit controlling devices or switch apparatus of the type usually interposed between the main line connections and the meter, but sometimes between the meter and the house circuits, to protect the house circuits and the meter from serious shortages on the branch circuits. Such switch apparatus generally comprises main line and branch fuses, and is so wired that the main line fuses protect the meter from the outside main line, while the branch fuses are placed between the meter and the house circuits. It also includes a switch for cutting off the house-circuit fuses from the line. The fuses and switch are usually enclosed in a box-like housing, and the entire unit is commonly referred to as an A switch.

In this type of circuit protecting apparatus, the branch or house circuit fuse or fuses must be accessible to the resident of the dwelling in order that he may replace the same in the event of blowing, and it is now common practice, and in many localities it is required, that safety features be incorporated in the switch apparatus, whereby access cannot be had to the fuses until the associated switch has been opened to cut them off the line. This is to prevent any possibility of a ground being accidentally established, with consequent injury to the person replacing a fuse.

The object of my invention is to provide an improved electrical switch apparatus of the type referred to in which the housing containing the switch and fuse mounting will be provided with a hinged cover that is normally closed and sealed, but may be opened by authorized persons when necessary to permit access to its contents, said cover having an opening through which the fuse socket or sockets are accessible when the cover is closed, such opening being provided with a hinged shutter adapted to closev it to prevent access to the fuses, and to be automatically locked in closed position when the switch is closed, and to be unlocked to permit it to be opened when the switch is opened; also to provide locking mechanism for the shutter of such character that the switch cannot be closed 1927. Serial No. 198,152.

without first closing the shutter and locking it in its closed position. Thus at no time is the fuse accessible while it is in a live condition. I accomplish this object as illustrated in the drawings and hereinafter described. What I believe to be new is set forth in the claims.

In the accompanying drawings which illustrate a preferred embodiment of my inven Fig. 3 is a vertical sectional view of the. housing showing its contents in side elevation and the lower portion of the meter case. In this view the parts are in the position they occupy when the switch and the shutter that protects the fuses are closed;

Fig. 4 is a view similar to Fig. 3, showing the switch open and the shutter unlocked and partly opened; and

Fig. 5 is a detail, being a partial vertical cross-section on line 5-5 of Fig. 4.

In the drawings, Fig. 1 illustrates a typical installation where a plurality of meters and A switches are grouped in a bank on a panel for connection with a plurality of distributing circuits. In said figure two meters 6 are shown, each being provided with a separate A switch 7, each of which switches, as shown in the illustration, is generally disposed below the meter with which it is associated, in such manner that the upper portion of the switch housing encloses the lower portion of the meter casing through which the meter connections extend. By reference to Fig. 1, it will be seen that each of said switches comprises a housing 8 in the form of a box-like structure preferably made of sheet metal and open at its upper end to receive the lower portion 9 of the meter casing. To the outer margin of the lower end of the housing is hinged a cover l0 which may be swungup over the housing to enclose the same,

and is adapted to be secured in closed posi-` tion in any suitable way, as by providing the cover with a slot 11 adapted to receive the upper end of a locking plate 12 perforated to receive a seal 13, as shown in Fig. 1. rlhe cover 10 is provided on its outer surface witha shutter 14 hinged thereto in any suitable way, as by a hinge 15, so that the shutter may be swung toward or fromthe outer surface of the cover. Said shutter is designed to close an opening 16 in the cover, which registers with the fuse socket or sockets which, as hereinafter described, are located within the housing. Around the opening 16 the cover is provided with an inwardly extending annular Vshield 17 of such shape and dimensions that its inner margin contacts with the fuse mounting around the fuse sockets when the cover'is closed, thereby preventing access to other parts of the housing through the opening 16. rlhe purpose of this shield is not only to Vprotect persons from accidentally coming in contact with live wires While removing Vor replacing a fuse, but alsovis to prevent connections tamperingV with the meter through the opening 16.

Mounted in the housing 8, and preferably Vsecured to the back wall or bottom surface the inner margin of the shield 17 contacts with its upper surface around the fuses 20, as clearly shown in said figures.

`In the illustrated construction the switch that is mounted on the base 18 is of the knife type comprising two pairs of contacts 21, 22, a

Yswitch blade 23 being pivoted at 24 to one of said contacts, asV 21, and being movable into or out of engagement with the other contact 22 by swinging the blade 23 about its pivot. The contacts 22 are preferablyY in the form of spring plates spaced apart sufciently to receive the blade23 betwen them. When the switch is closed the blades 23 extend. longitudinally of the housing, and when the switch is opened they are swung up toward a transverse position, as illustrated in Fig. 4. In the construction illustrated the switch comprises two of the blades 23 which are arranged to be moved simultaneously into or out of contact with the contacts 22 by means of a crank shaft or bail 25, the ends of which are journaled in the sidewalls ofthe housing, as best shown in Fig. 2. As therein shown, one end 26 of said crank shaft extends through the side wall in which it is mounted, and is provided with a bent end or handle 27 for conveniently rocking theV crank shaft from outsidethe housing. A stop 28 secured to the side wall of the housing limits the movement of the handle 27 in one direction. The intermediate or crank portion of the crank shaft 25 is operatively connected with the switch blades 23, to provide for moving said blades into or out of closed position by the rocking of said crank shaft, by means of standards 29 that are secured to the blades 23 and project therefrom, preferably at right angles. Each of these standards is provided with a notch 30 to receive the crank portion of the crank shaft 25, and they are made of fiber or other suitable insulating material so that the crankshaft is insulated from the switch parts. It will be apparent from the foregoing description that whenthe switch is closed, by rocking the crank shaft 25 in a counterclockwise direction as viewed in Fig. 3, the switch blades 23 may be swung to the position shown in Fig. 4, thereby opening the switch, and that byjrocking said crankshaft in the opposite direction the switch may be closed.

rolockthe shutter 14, that closes the opening 16, in its closed position, I provide a bolt 31V which is movable into kand out of a slot or hole in a tang 32 at the free edge of the shutter 14 and extending at approximately right angles to the plane of the shutter so that when theshutter is closed said tang extends through a slot 33 in the coverlO. 1n the illustrated construction the tang 32l is at the lower margin of the shutter, and it is engaged by the upper endl of the bolt 31, which is mounted on the inner face of the cover 10 to slide up and down. To this end, said bolt is provided with a laterally projecting ange 35 provided with slots through which extend pins 36 which hold the. boltin its proper position, but permit it to move endwise. At

which is connected with said bolt, its other end being connected to the upper end portion of a pivoted latch 39 in such manner that said spring functions not only to move the bolt 31 to its operative position, but also to normally hold the upper end portion of the latch 39 in engagement with or in proximity to the inner face of the cover 10.

The latch 39 is mounted between its ends on a horizontal pivot 40 mounted in a bracket 41 secured to the inner face of the cover 10 at path of the tang 32, and when the shutter 14 1"" is closed said tang engages the upper end of said latch and rocks it against the ten- Lsion. of the spring 38 to the position shown in Fig. 3. The upperend of the bolt 31 is beveled, as shown .at 42 in Fig. 3, so that as `the shutter 14 moves to its closed position the in said tang, thereby locking the shutter in its'closed position. The latch 39 is provided at its lower end with a shoulder 43 that lies farenough above the arm 37 on the bolt to permit the crank shaft 25 to be interposed between said parts when the switch is opened and the bolt 31 is thereby moved downward out of operative position. In this operation, as shown in Fig. 4, a space 44 is provided in which the crank portion of the crank shaft 25 lies, the shoulder 43 then extending above and across the path of the crank shaft so that it cannot be swung in a clockwise direction as viewed in Fig. 4, far enough to close the switch, but may be swung sufficiently to permit the bolt 31 to move up far enough to lock the shutter 14 in its closed position.

The operation is as follows: When the switch and the shutter 14 are both closed the shutter is locked in its closed position by the bolt 31, the upper end of which is then in engagement with the tang 32, and the crank shaft25 and other parts occupy the positions shown in Fig. 3, at which time, as will be seen,

the upper end of the latch 39 presses against the inner margin of the tang under the action of the spring 38, so that it tends to open the shutter. When the shutter is closed, the fuses are, of course, inaccessible. IVhen it iis desired to open the shutter it is necessary to move the bolt 31 downward out of engagement'with the tang 32, and this can be done only by rocking the crank shaft in a counterclockwise direction and thereby opening the switch. When said crank shaft is so rocked it engages the arm 37 and through said arm moves the bolt 31 downward to the position shown in Fig. 4. As soon as the tang 32 is released from the bolt the upper end of the latch 39 presses the lower vend of the shutter 14 outward so that these parts then assume the position shown in Fig. 4, and the shutter may be swung up to fully expose the opening 16. This movement of the latch 39 carries its lower end inward, or to the right as viewed in Figs. 3 and 4, so that its shoulder 43 is in position to intercept the crank shaft if it should be swung in a clockwise direction, or toward its switch closing position. Evident ly, therefore, the switch cannot be closed so long as the latch 39 occupies the position shown in Fig. 4, which position it maintains so long as the shutter 14 is away from its closed position. When it is desired to close the switch the shutter 14 is first closed, whereby the tang 32 moves the upper end of the latch 39 inward and its lower end outward out of the path of the crank shaft, thereby permitting said shaft to be swung in a clockwise direction toits switch closing position. As it is desirable that the shutter 14 be locked in its closed position as soon as it is completely closcd, the space 44 between the arm 37 and the shoulder 43 is made wide enough to permit the crank shaft to be swung upward sufficiently to permit the bolt 31 to move to locking position, notwithstanding that the latch 39 may still be iin position to prevent the closing of the switch. By this arrangement, as soon as the lid 14 is completely closed it will be locked in its closed position before the crank shaft is operated to close the switch. The shoulder 43 is, however, made wide enough so that it is always in a position to intercept the crank shaft and prevent closing of the switch unless the shutter be completely closed. l

l/Vhen the housing cover 10 is closed the shield 17- completely cuts ofi' access to the interior of the housing through the opening 16, so that tampering with any of the enclosed part-s is prevented, and there is no danger that one removing or replacing a fuse will come in contact with any live connection.

In the drawings I have shown my improved switch apparatus as equipped with auxiliary switches for meter testing, and with interconnecting sections of conduit, as shown and described in my copending application, Serial No. 142,289, but as such parts have nothing to do with my present invention it has not been deemed necessary to described them. It should be understood that while I have described specifically the embodiment of my invention illustrated in the accompanying drawings the claims hereinafter made are not intended to be limited to such specific construction except in so far as the same may be particularly claimed, as various modifications may be made without departing from the generic features of invention pointed out in the broader claims.

What I claim as my invention and desire to secure by Letters Patent, is-

1. In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening, a fuse mounting in said housing accessible through said opening, a hinged shutter mounted on the cover and movable into and out of position to close said opening, a switch in said housing in circuit with said fuse mounting, a bolt mounted to slide on the innei` face of the cover into and out of position to lock the shutter closed, a crank shaft operable to open and close said switch and to move said bolt out of operative position after the switch has4 been opened, and means on the hinged cover for preventing switch closing movement of said crank shaft until the shutter is closed.

2. n aswitch apparatus ofthe character described, the combination of a housing having ahinged co-ver provided with an opening,

a fuse mounting in said housing accessible Vthrough said opening,

tion to lock the shutter closed, a crankshaft operable to open and close said switch and to move said bolt out of operative position after the switch has been opened, and a latch Vpivotally mounted on `said hinged cover and operating to prevent switch closing movement of said crank shaft until the shutter is closed.

3. In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening, a fuse mounting in said housing accessible through said opening, 'a hinged shutter mounted on the cover and movable into and out of position to close said opening, a switch in said housing in circuit with said fuse mounting, a bolt Ymounted Vto slide von the inner face of the cover into and out of position to lock the shutter closed, a crank shaft operable to open and close said switchY and to move said bolt out of operative position after the switch has been opened, and a latch pivotally mounted on said hinged cover spaced from the hinge axis of the shutter and movable into position to intercept said crank shaft andv prevent closing ofthe switch when the shutter is open, and being movable out of such'position by the closure of the shutter. Y g

4. In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening, a fuse mounting in said housing accessible through said opening, a hinged shutter mounted on the cover and movable into and out of position to close said opening, a'switch V in said housing in circuit with said fuse mounting, a bolt mounted' to slide on the inner face of the cover into and out of position to lock the shutter closed, a crank shaft operable to open and close said switch and to move said bolt out of operative position after the switch has `been opened, a latch pivotally mounted on the cover and movable into position to intercept said crank shaft and prevent closing of the switch when the shutter is open, and being movable out of such position by the closure of the shutter, and a spring connected with said bolt and with said latch for normally moving said bolt and said latch to their respective locking positions.

5. In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening and a shield at the inner rside of said cover around said opening, a fuse mounting in said Ahousing accessible through said opening and adapted `to be engaged by said shield to prevent access .to the interior of the housing around said fuse mounting, a hinged vshutter mounted on the cover for closing said opening, a switch in said housing in circuit with said fuse mounting, locking means'mounted on the inner *face of the vcover and adapted to lock said shutter in its closed position, a single means operable to open and close said switch and to actuate saidlocking means to release the shuttenand means mounted on said cover for preventing Vclosure of the switch until said shutter hasl been closed.

6. Ina switch apparatus of the character described, the combination of a housing having a hinged cover, a switch in said housing, a crankshaft operable to open and closev said switch, slidable means in said housingv normally locking saidcover closed, said crank shaft moving said slidable means out of locking position after said switch has been opened, and biased means within said housing for normally urging said cover )open `whereby the cover is automatically opened when said slidable means has been moved out of locking position, said crank shaft being held between said slidable means and said biased means for preventing'the closing of said switch when said cover is open. i i

7 In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening, a hinged shutter mounted on the cover and movable into and out of position to close said opening, a fuse mounting in said housing accessible through said opening, a switch in said housing in circuit with'said `fuse mounting, locking means mounted ony the inner face of said cover for normally holding said shutter closed, a crank shaft operable to open and close said switch `and to move said means out of holding position after said switch has been opened, pivotal means mounted on said'cover for intercepting said crank shaft and preventing closing of said switch when said shutter 1s open and being movable out of such position by the closure of said shutter, and means connected with said locking means and withvsaid pivotal means for normally moving said two means to their respective locking positions and for normally urging said pivotal means against said shutter whereby said shutter is automatically opened when said locking means .has been moved out of holding position. A

8. In a switch apparatus of the character described, the combination of a housing having a hinged cover provided with an opening, a hinged shutter mounted on the cover and movable into and out of position to close said opening, a fuse mounting vin -said housing accessible through said opening, a switch in said housing in circuit with said fuse mounting, locking means mounted on the inner face of said cover for normally holding said shutter closed, a crank shaft operable to open and close said switch and to move said means out of holding position after said switch has been opened, pivotal means mounted on said cover for intercepting said crank shaft and preventing closing of said switch when said shutter is open and being movable out of such position by the closure of said shutter, and a spring connected with said locking means and with said pivotal means for normally moving said two means to their respective locking positions and for normally urging said pivotal mea-ns against said shutter whereby said shuter is automatically opened when said locking means has been moved out of holding position.

9. In a switch apparatus of the class described, the combination of a housing having a hinged cover, a switch in said housing, a bolt mounted to slide in said housing into and out of position to lock said cover closed and having a projection thereon, a crank shaft operable to open and close said switch and to move said bolt out of operative position by contacting with said projection after said switch has been opened, a latch pivotally mounted in said housing and provided with a shoulder and movable into position to intercept said crank shaft between said shoulder and said projection and prevent closing said switch when the cover is open, said latch being movable out of such position by the closure of said cover, and a sprin connected with said bolt and with said latc for normally moving said bolt and said latch to their respective locking positions.

DON R. FURNAS. 

